Thursday, January 21, 2016

2015 is the hottest year on record by a massive 0.13°C

Dr Gavin Schmidt, Director of the Goddard Institute of Space Studies (GISS), NASA and Dr Thomas Karl, Director of the National Centers for Environmental Information (NCEI), NOAA have just given a press conference to to announce the annual average global temperature results and discuss the most important weather and climate events of the year.

You will not be surprised to know that 2015 was yet another hottest year ever recorded in the instrumental record, beating 2014 by a huge 0.13 °C. It was 1.25 °C hotter than pre-industrial. It is now 106 years since there was a "coldest year on record". (Gavin Schmidt said that 2015 would have broken the record even without the El Niño, though presumably by not as much.)

Anyone who tries to tell you it hasn't warmed since 1996, or 1997, or 1998, is dead wrong. See for yourself:

Note about the ballpark: I took the pre-industrial benchmark to be 0.3 °C cooler than 1900, from this recent article by Professor Michael Mann in Huffington Post.

Decadal changes

On a decadal time scale, last year is hauling the chart upwards, being way above the latest decadal average. Below is a chart showing decadal changes, starting from the sixth year in each decade to show the full decade up to December 2015.

Hottest years in order

Below is a chart showing the hottest years, starting with 2015 on the left. As the chart and the table underneath show, fifteen of the sixteen hottest years were this century. 2015 broke the mould by being a huge 0.13 °C hotter than the previous hottest year. The previous biggest jump (just in the top 20) was less than half that, at 0.06 °C. I checked again. There have been two occasions when there were bigger hikes from one year to the next in the past twenty years: 1997 to 1998 and 2004 to 2005. It has happened on average about one in ten years since 1880.

Watch the world warming

Stay safe

As if to emphasise the fact that climate change brings extreme weather, I see that the east coast of the USA is bracing for the possibility of a "blockbuster" storm event, an "epic blizzard" which could bring:

Record snowfalls, particularly to Washington DC (big snows elsewhere but unlikely to be a record)

Fierce winds

Storm surges, and twenty foot waves along the mid-Atlantic coast (especially from New Jersey to the Delmarva Peninsula)

blackouts for lots and lots of people

A raucous din from science deniers saying "see, it's record snow. Global warming is a hoax".

Or it might not. It's still too soon to say, although Bob Henson wrote: "computer models were in remarkable agreement late Tuesday" - then again - models, huh!

Protests from deniers at WUWT

WUWT are already protesting the hot planet. Bob Tisdale has posted two protest articles in quick succession (archived here and here). He put "record high" in quotation marks presumably to show that he doesn't believe the data. He makes a habit of accusing scientists of fraud and fakery. He's not a man of good character. A sleaze as well as a science denier. Bob wrote:

I suspect Tom Karl and Gavin Schmidt won’t bother to tell the public that lower troposphere temperature data were far from record highs in 2015.

He was wrong. They did "tell the public" about the lower troposphere temperatures in their main presentation - and said the annual temperature wasn't a record (without prompting by anyone).

Bob's also wrong about the upper air temperatures being far from record highs. On an annual basis the lower troposphere temperature record makes 2015 the third hottest year on record, which is not far at all. As well as that, the last three months of the record each broke the record for that month. That is, there was a record hot October, a record hot November and a record hot December.

Bob Tisdale didn't bother to tell the WUWT public about the Berkeley Earth record

What Bob Tisdale didn't tell his readers was that as far as the surface temperatures go (which is where we live, after all), there is another independent data set that also posted a record hot year. Elizabeth Muller of Berkeley Earth wrote:

According to new Berkeley Earth analysis, 2015 was unambiguously the hottest year on record. For the first time in recorded history, the Earth’s temperature is clearly more than 1.0 C (1.8 F) above the 1850-1900 average. 2015 was approximately 0.1 degree C (about 0.2 degrees F) hotter than 2014, which had tied with 2005 and 2010 as the previous hottest years. 2015 set the record with 99.996% confidence. The analysis covered the entire surface of the Earth, including temperatures from both land and oceans.

The most important things we can do to mitigate global warming include energy efficiency and the increased use of renewables, natural gas, and nuclear power. It is time for us to stop being picky about which is the very best solution to global warming – we need all solutions that are available to us today

First, they discussed the atmosphere data sets at length including the balloon data which does appear to be showing a record high.

Second, if the satellite data sets hit a record peak in 2016 bang goes all the "no global warming since..." arguments. The deniers will not be able to turn around and try and discredit satellite data after promoting it so much. Even Dr Roy Spencer has given himself an out on that one.

Both the NOAA and NASA figures topped my mid/late-2015 predictions that 2015 would smash the existing records by >0.13 °C and >0.10 °C respectively. And even more amazingly, in today's news conference Gavin Schmidt and Thomas Karl both agreed with the Met Office's prediction that 2016 will be hotter than 2015.

You write "2015 broke the mould by being a huge 0.13 °C hotter than the previous hottest year. The previous biggest jump (just in the top 20) was 0.6 °C." I wonder if you meant 0.06 °C, or am I missing something?

I found it interesting that both Schmidt and Karl mentioned that it was "virtually certain" (94% NASA, 99% NOAA) that 2015 is the warmest year on record. This means that the Watties won't be able to play the game they played last year when there was some overlap in the uncertainty ranges between 2014 and previous records.

They also spent a bit of time and a slide addressed to Rep. Smith, who will no doubt be upset with this result.

My main take from that observation is just how very much any two successive annual values have to be before we do get an actual "higher value" that doesn't allow the completely specious "reasoning" that no warming is occurring as e saw last year. It's always the trend, and the trend in the surface data is clear.

The deniers-in-Chief (James Inhofe, Lamar Smith) will have their chance to "disprove" the data in a couple days because Washington is about to get hit with a monster snowstorm. It won't be particularly cold (forecast is for just below the freezing mark), but, as we all know, that won't matter to them. -- Dennis

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All you need to know about WUWT

WUWT insider Willis Eschenbach tells you all you need to know about Anthony Watts and his blog, WattsUpWithThat (WUWT). As part of his scathing commentary, Wondering Willis accuses Anthony Watts of being clueless about the blog articles he posts. To paraphrase:

Even if Anthony had a year to analyze and dissect each piece...(he couldn't tell if it would)... stand the harsh light of public exposure.

Definition of Denier (Oxford): A person who denies something, especially someone who refuses to admit the truth of a concept or proposition that is supported by the majority of scientific or historical evidence.
‘a prominent denier of global warming’
‘a climate change denier’

Alternative definition: A former French coin, equal to one twelfth of a Sou, which was withdrawn in the 19th century. Oxford. (The denier has since resurfaced with reduced value.)